Composition for forming a resist underlayer film, and pattern-forming method

ABSTRACT

A composition for forming a resist underlayer film is provided, which contains: a calixarene-based compound obtained from a calixarene by substituting at least a part of hydrogen atoms each on phenolic hydroxyl groups comprised in the calixarene, with a monovalent organic group having 1 to 30 carbon atoms; and an organic solvent. The monovalent organic group preferably includes a crosslinkable group. A part of hydrogen atoms each on phenolic hydroxyl groups of the calixarene-based compound is preferably substituted. The ratio of the number of substituted phenolic hydroxyl groups to the number of unsubstituted phenolic hydroxyl groups in the calixarene-based compound is preferably no less than 30/70 and no greater than 99/1.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 14/642,857 filed Mar. 10, 2015, which in turn is acontinuation application of International Application No.PCT/JP2013/074164, filed Sep. 6, 2013, which claims priority to JapanesePatent Application No. 2012-198837, filed Sep. 10, 2012. The contents ofthese applications are incorporated herein by reference in theirentirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a composition for forming a resistunderlayer film, and a pattern-forming method.

2. Discussion of the Background

In manufacturing integrated circuit elements and the like, apattern-forming method utilizing a multilayer resist process has been inwidespread use to meet miniaturization of processing size. With respectto the multilayer resist process, in general, a composition for forminga resist underlayer film is applied on the upper side of a substrate toprovide a resist underlayer film, and a resist composition is furtherapplied on the upper side of resist underlayer film to provide a resistfilm. Then, a transfer of a mask pattern by way of irradiation withexposure light and a subsequent development yields a resist pattern.Subsequently, the resist pattern is transferred to the resist underlayerfilm by dry etching. Finally, the resist underlayer film pattern istransferred to the substrate by dry etching, whereby the substrate witha desired pattern can be obtained.

In general, materials having a high carbon content are used for theresist underlayer film provided directly on the substrate. Such a highcarbon content leads to an increase of etching selectivity in theprocessing of the substrate, which enables more precise patterntransfer. Known compositions for forming such a resist underlayer filminclude: a composition that contains a thermosetting phenol novolakresin (see PCT International Publication No. 2009/072465); a compositionthat contains an acenaphthylene resin (see Japanese Unexamined PatentApplication, Publication Nos. 2000-143937 and 2001-40293); and acomposition that contains a calixarene (see Japanese Unexamined PatentApplication, Publication No. 2008-116677), and these compositions canreportedly provide a resist underlayer film exhibiting superior etchingresistance.

On the other hand, in these days, formation of a pattern on a substratehaving a plurality of types of trenches, in particular, trenchesdiffering from one another in terms of an aspect ratio has been executedmore frequently.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, a composition forforming a resist underlayer film includes a calixarene-based compoundand an organic solvent. The calixarene-based compound is obtained from acalixarene by substituting at least a part of hydrogen atoms each onphenolic hydroxyl groups included in the calixarene, with a monovalentorganic group having 1 to 30 carbon atoms.

According to another aspect of the present invention, a pattern-formingmethod includes in a following order of: providing a resist underlayerfilm directly or indirectly on a substrate; forming a resist patterndirectly or indirectly on the resist underlayer film; forming a patternon the substrate through dry etching of the resist underlayer film, thesubstrate, or both the resist underlayer film and the substrate usingthe resist pattern as a mask; and removing the resist underlayer filmremaining on the substrate using a basic solution. The method furtherincludes subjecting the resist underlayer film to heating or an acidtreatment before removing the resist underlayer film. The resistunderlayer film is provided using the composition for forming a resistunderlayer film.

DESCRIPTION OF EMBODIMENTS

According to an embodiment of the invention made for solving theaforementioned problems, a composition for forming a resist underlayerfilm contains:

a calixarene-based compound obtained from a calixarene by substitutingat least a part of hydrogen atoms each on phenolic hydroxyl groupscomprised in the calixarene, with a monovalent organic group having 1 to30 carbon atoms (hereinafter, may be also referred to as “(A) compound”or “compound (A)”); and

an organic solvent (hereinafter, may be also referred to as “(B) organicsolvent” or “organic solvent (B)”).

According to another embodiment of the present invention, apattern-forming method includes in the following order of:

providing a resist underlayer film directly or indirectly on asubstrate;

forming a resist pattern directly or indirectly on the resist underlayerfilm;

forming a pattern on the substrate through dry etching of the resistunderlayer film, the substrate, or both the resist underlayer film andthe substrate using the resist pattern as a mask; and

removing the resist underlayer film remaining on the substrate using abasic solution,

wherein the method further includes subjecting the resist underlayerfilm to heating or an acid treatment before removing the resistunderlayer film, and

wherein the resist underlayer film is provided using the composition forforming a resist underlayer film according to the embodiment of thepresent invention.

The term “calixarene-based compound” as referred to herein means acompound obtained from a calixarene by substituting at least a part ofhydrogen atoms each on phenolic hydroxyl groups included in thecalixarene, with a monovalent organic group having 1 to 30 carbon atoms.The term “calixarene” as referred to means a cyclic oligomer derivedfrom a plurality of aromatic rings to which a hydroxy group bonds, or aplurality of heteroaromatic rings to which a hydroxy group bonds,through linking to form a ring via a hydrocarbon group. The term“phenolic hydroxyl groups included in a calixarene” as referred to meansall of the hydroxy groups which directly bond to the aromatic rings orthe heteroaromatic rings each included in the calixarene, and includesphenolic hydroxyl groups derived from any of a phenolic compound and analdehyde compound used in the formation of the calixarene. The term“organic group” as referred to means a group having at least one carbonatom(s).

The composition for forming a resist underlayer film according to theembodiment of the present invention enables a resist underlayer filmsuperior in flatness, solvent resistance and outgas-inhibitory abilityto be formed. The pattern-forming method according to the anotherembodiment of the present invention enables a resist underlayer filmsuperior in flatness, solvent resistance and outgas-inhibitory abilityto be formed, and in turn, a favorable pattern to be formed. Therefore,the composition for forming a resist underlayer film and thepattern-forming method can be suitably used for producing semiconductordevices in which further progress of miniaturization is expected in thefuture. Hereinafter, embodiments of the present invention are explainedin detail.

Composition for Forming Resist Underlayer Film

The composition for forming a resist underlayer film contains thecompound (A) and the organic solvent (B). The composition for forming aresist underlayer film may contain a resin (hereinafter, may be alsoreferred to as “(C) resin” or “resin (C)”) as a favorable component, andmay contain other optional component within a range not leading toimpairment of the effects of the present invention.

The composition for forming a resist underlayer film enables a resistunderlayer film superior in flatness to be formed. The composition forforming a resist underlayer film can be suitably used for, for example,a substrate having a plurality of types of trenches; even in a casewhere the plurality of types of trenches differ from one another interms of an aspect ratio (for example, a ratio of the width to the depthof the trench), and further even in a case where the difference in theaspect ratio from one another is significant, or for example, the ratioof the maximum value to the minimum value of the aspect ratios is noless than 10, the composition for forming a resist underlayer film canbe suitably used, and a resist underlayer film superior in flatness canbe formed. Such a substrate having a plurality of types of trenches isexemplified by a SiO₂ stepped substrate in which one or two or moretypes of trenches having a width of 20 nm to 300 nm, a pitch of 1.2 to 5times the width, and a depth of 20 nm to 300 nm; trenches having a widthof 0.3 μm to 10 μm, and a depth of 20 nm to 300 nm (open spaces), andthe like are provided in combination; and the like. Moreover, accordingto the composition for forming a resist underlayer film, the resistunderlayer film formed also has superior solvent resistance and outgasinhibitory ability. Furthermore, the composition for forming a resistunderlayer film can be applied on silicon wafers of a size of 450 mm orthe like with superior intra-plane uniformity.

Although not necessarily clarified, the reason for achieving theabove-described effects due to the composition for forming a resistunderlayer film having the constitution described above is presumed asin the following, for example. Specifically, since the compound (A) hasan appropriate and substantially uniform molecular weight, and thehydrogen atom of a part or all of the phenolic hydroxyl groups aresubstituted with the monovalent organic group, the compound (A) exhibitsmoderate sublimability, with improved insolubility in a solventcontained in typical resist compositions, as well as improved solubilityin a solvent contained in the composition for forming a resistunderlayer, and further the viscosity of the composition for forming aresist underlayer film is decreased appropriately. As a result, thecomposition for forming a resist underlayer can be suitably used for amaterial for an underlayer to be coated, and enables a resist underlayerfilm superior in flatness, solvent resistance and outgas-inhibitoryability to be formed.

Hereinafter, each component will be explained.

(A) Compound

The compound (A) is a compound obtained from a calixarene bysubstituting at least a part of hydrogen atoms each on phenolic hydroxylgroups included in the calixarene, with a monovalent organic grouphaving 1 to 30 carbon atoms. Due to containing the compound (A), thecomposition for forming a resist underlayer film can provide a resistunderlayer film superior in flatness, solvent resistance andoutgas-inhibitory ability. The composition for forming a resistunderlayer film may contain one, or two or more types of the compound(A).

The monovalent organic group having 1 to 30 carbon atoms is exemplifiedby: a monovalent hydrocarbon group; a group that includes a heteroatom-containing group between two carbon atoms in the monovalenthydrocarbon group; a group obtained by substituting a part or all ofhydrogen atoms included in any one of these groups with a substituent;and the like.

The monovalent hydrocarbon group is exemplified by a monovalent chainhydrocarbon group having 1 to 30 carbon atoms, a monovalent alicyclichydrocarbon group having 3 to 30 carbon atoms, a monovalent aromatichydrocarbon group having 6 to 30 carbon atoms, and the like.

Examples of the monovalent chain hydrocarbon group include:

alkyl groups such as a methyl group, an ethyl group, a propyl group, abutyl group and a pentyl group;

alkenyl groups such as an ethenyl group, a propenyl group, a butenylgroup and a pentenyl group;

alkynyl groups such as an ethynyl group, a propynyl group, a butynylgroup and a pentynyl group; and the like.

Examples of the monovalent alicyclic hydrocarbon group include:

monocyclic cycloalkyl groups such as a cyclopropyl group, a cyclobutylgroup, a cyclopentyl group and a cyclohexyl group;

monocyclic unsaturated alicyclic hydrocarbon groups such as acyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, acyclohexenyl group and a cyclopentanedienyl group;

polycyclic cycloalkyl groups such as a norbornyl group, an adamantylgroup, a tricyclodecyl group and a tetracyclododecyl group;

polycyclic unsaturated alicyclic hydrocarbon groups such as anorbornenyl group, a tricyclodecenyl group, a tetracyclododecyl groupand a norbornanedienyl group; and the like.

Examples of the monovalent aromatic hydrocarbon group include:

aryl groups such as a phenyl group, a tolyl group, a xylyl group, amesityl group, a naphthyl group, a methylnaphthyl group, an anthrylgroup and a methylanthryl group;

aralkyl groups such as a benzyl group, a phenethyl group, anaphthylmethyl group and an anthrylmethyl group; and the like.

Examples of the hetero atom-containing group include —O—, —S—, —NR′—,—CO—, —CS—, groups obtained by combining two or more of these groups;and the like, wherein R′ represents a monovalent hydrocarbon grouphaving 1 to 10 carbon atoms.

Examples of the group that includes a hetero atom-containing groupbetween two carbon atoms in the monovalent hydrocarbon group include:

chain groups including for example, alkoxyalkyl groups,alkylsulfanylalkyl groups, alkyliminoalkyl groups, acylalkyl groups,alkylthiocarbonylalkyl groups; and

cyclic groups including for example, cyclic ether groups, cyclicthioether groups, cyclic amino groups, cyclic ketone groups, cyclicthioketone groups.

Examples of the substituent include: halogen atoms such as a fluorineatom, a chlorine atom, a bromine atom and an iodine atom; a hydroxygroup; a carboxy group; a cyano group; a nitro group; alkoxy groups;alkoxycarbonyl groups; alkoxycarbonyloxy groups; acyl groups; acyloxygroups; and the like.

The monovalent organic group preferably includes a crosslinkable group.When the monovalent organic group includes the crosslinkable group, thestrength of the resist underlayer film formed can be increased, andorganic solvent resistance can be improved owing to crosslinking betweenthe compounds (A) or between the compound (A) and the resin (C)described later. The term “crosslinkable group” as referred to means agroup capable of forming a covalent bond between identical or differentmolecules.

Examples of the crosslinkable group include groups include: groupsincluding a polymerizable carbon-carbon double bond; groups including apolymerizable carbon-carbon triple bond; an epoxy group; alkoxymethylgroups; a formyl group; an acetyl group; dialkylaminomethyl groups; adimethylolaminomethyl group; and the like. Of these, groups including apolymerizable carbon-carbon double bond are preferred, and a vinylgroup, a vinylphenyl group, and a (meth)acryloyl group are preferred.

Examples of the monovalent organic group including the crosslinkablegroup include groups represented by the following formulae (a) to (c),and the like.

In the above formulae (a) to (c), R^(a) and R^(a′) each independentlyrepresent a single bond or an alkanediyl group having 1 to 10 carbonatoms; R^(a″) represents a single bond, an alkanediyl group, ahydroxyalkanediyloxy group or (R″O)_(i); R″ represents an alkanediylgroup; “i” is an integer of 1 to 10; and R^(b), R^(b′), R^(b″), R^(c),R^(c′), R^(c″), R^(d), R^(d′) and R^(d″) each independently represent ahydrogen atom or a monovalent hydrocarbon group.

Preferably “i” is an integer of 1 to 4, more preferably 1 to 3, andstill more preferably 1 or 2.

Examples of the alkanediyl group which may be represented by R^(a),R^(a′) and R^(a″) include an ethanediyl group, a propanediyl group, abutanediyl group, and the like.

Examples of the hydroxyalkanediyloxy group which may be represented byR^(a″) include a 2-hydroxypropanediyloxy group, a 2-hydroxybutanediyloxygroup, and the like.

Examples of (R″O), which may be represented by R^(a″) include anoxyethanediyl group, an oxypropanediyl group, an oxybutanediyl group, anoxyethanediyloxyethanediyl group, an oxypropanediyloxypropanediyl group,an oxybutanediyloxybutanediyl group, and the like.

Examples of the monovalent organic group represented by the aboveformula (a) include a vinyl group, an allyl group, a 3-butenyl group, a2-methyl-2-propenyl group, a 3-methyl-2-propenyl group, and the like.

Examples of the monovalent organic group represented by the aboveformula (b) include a 4-vinylbenzyl group, a 4-vinylphenyl group, a2-vinylbenzyl group, a 4-allylbenzyl group, and the like.

Examples of the monovalent organic group represented by the aboveformula (c) include a (meth)acryloyl group, a (meth)acryloyloxyethylgroup, a (meth)acryloyloxyethoxyethyl group, a(meth)acryloyloxy-2-hydroxypropyl group, a (meth)acryloyloxypropylgroup, a (meth)acryloyloxybutyl group, and the like.

Of these, the monovalent organic group is preferably a vinyl group, anallyl group, a 2-methyl-2-propenyl group, a 3-methyl-2-propenyl group, a4-vinylbenzyl group, a 4-vinylphenyl group, a (meth)acryloyl group, a(meth)acryloyloxyethyl group, a (meth)acryloyloxyethoxyethyl group, or a(meth)acryloyloxy-2-hydroxypropyl group.

As the monovalent organic group, a group that does not substantiallyinclude a crosslinkable group is also preferred. Due to the monovalentorganic group not substantially including a crosslinkable group, filmshrinkage that occurs in the formation of the resist underlayer film canbe inhibited, and as a result, the flatness of the resist underlayerfilm formed can be improved.

Examples of the monovalent organic group that does not include acrosslinkable group include:

alkyl groups such as an ethyl group, a propyl group and a butyl group;

cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, acycloheptyl group, a cyclooctyl group, a norbornyl group and anadamantyl group;

aromatic hydrocarbon groups such as a phenyl group, a tolyl group, axylyl group, a mesityl group, a benzyl group, a phenethyl group, anaphthyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a1-naphthylethyl group, a 2-naphthylethyl group, an anthryl group and a2-anthrylmethyl group;

hydroxy group-containing alkyl groups such as a 2,3-dihydroxypropylgroup, a 3-phenoxy-2-hydroxypropyl group and a 2,3-dihydroxybutyl group;

alkoxycarbonyl-containing groups such as a t-butoxycarbonylmethyl group,a t-butoxycarbonyl group, a t-pentyloxycarbonylmethyl group and at-pentyloxycarbonyl group; and the like.

Of these, cycloalkyl groups, aromatic hydrocarbon groups, hydroxygroup-containing alkyl groups, and alkoxycarbonyl-containing groups arepreferred, and a cyclopentyl group, a cyclohexyl group, a benzyl group,a 2-naphthylmethyl group, a 2,3-dihydroxypropyl group, a3-phenoxy-2-hydroxypropyl group, a t-butoxycarbonylmethyl group, and at-butoxycarbonyl group are more preferred.

Moreover, a monovalent organic group that can be eliminated upon abaking treatment, an acid treatment or the like is also preferred as themonovalent organic group. When the monovalent organic group that can beeliminated upon a baking treatment, an acid treatment or the like isselected as a substituent of the phenolic hydroxyl group, the resistunderlayer film remaining after the pattern formation can be removedusing a basic solution. In such a case, the resist film can be removedwithout employing an ashing treatment or the like, and thus, theinfluence of the ashing treatment or the like on the substrate can beminimized.

It is preferred that a part of hydrogen atoms each on phenolic hydroxylgroups of the compound (A) is substituted. In the compound (A), when apart of hydrogen atoms each on phenolic hydroxyl groups included in acalixarene is substituted, the compound (A) includes at least onephenolic hydroxyl group(s). Accordingly, the wettability of thecomposition for forming a resist underlayer film on a substrate can beimproved, and as a result, adhesiveness of the formed resist underlayerfilm to a substrate can be improved.

The ratio of the number of substituted phenolic hydroxyl groups to thenumber of unsubstituted phenolic hydroxyl groups (the number ofsubstituted phenolic hydroxyl group/the number of unsubstituted phenolichydroxyl group) in the compound (A) is preferably no less than 30/70 andno greater than 99/1, more preferably no less than 40/60 and no greaterthan 95/5, still more preferably no less than 50/50 and no greater than90/10, and particularly preferably no less than 60/40 and no greaterthan 85/15. The term “substituted phenolic hydroxyl group” as referredto means a phenolic hydroxyl group whose hydrogen atom is substitutedwith a monovalent organic group having 1 to 30 carbon atoms. When thenumber ratio falls within the above range, the solubility of thecompound (A) in the organic solvent (B) can be increased, and thewettability of the compound (A) on a substrate can be further increased.As a result, the adhesiveness of the resist underlayer film formed fromthe composition for forming a resist underlayer film to a substrate canbe further improved. In a case where the composition for forming aresist underlayer film contains a plurality of types of compound (A),the number ratio means a ratio of the number of substituted phenolichydroxyl groups to the number of unsubstituted phenolic hydroxyl groupseach included in a certain mass of mixture constituted with theplurality of types of compound (A).

It is to be noted that the number ratio can be calculated based on a¹H-NMR measurement of the compound (A). The calculation method may beappropriately selected according to the structure and/or synthesismethod of the calixarene-based compound. Examples of the calculationmethod include: a method in which the number ratio is calculated from anarea of a peak derived from hydrogen atoms on aromatic rings to which anunsubstituted phenolic hydroxyl group bonds and an area of a peakderived from hydrogen atoms on aromatic rings to which a substitutedphenolic hydroxyl group bonds; a method in which the number ratio iscalculated from a ratio of an area of a peak derived from hydrogen atomsincluded in unsubstituted phenolic hydroxyl groups, an area of a peakderived from hydrogen atoms included in calixarene-based compounds, andan area of a peak derived from hydrogen atoms included in substituentson substituted phenolic hydroxyl groups; and the like.

The compound (A) is preferably derived from a compound obtained bysubjecting a compound represented by the following formula (1) and acompound represented by the following formula (2) to a condensationreaction. In this instance, the compound (A) can be obtained bysubjecting a hydroxy compound represented by the following formula (1)and an aldehyde compound represented by the following formula (2) to acondensation reaction to obtain a calixarene, and substituting thehydrogen atom of phenolic hydroxyl groups included in the calixarenewith a monovalent organic group having 1 to 30 carbon atoms.

In the above formula (1), Y represents a hydrocarbon group having 1 tocarbon atoms; q is an integer of 0 to 7; p is an integer of 1 to 3,wherein a sum of p and q is no less than 1 and no greater than 8; and kis 0 or 1, wherein in a case where q is no less than 2, a plurality ofYs are identical or different.

In the above formula (2), X represents a substituted or unsubstitutedhydrocarbon group having 1 to 30 carbon atoms and having a valency of j,or hydrogen atom; and j is 1 or 2.

The hydrocarbon group having 1 to 10 carbon atoms represented by Y isexemplified by hydrocarbon groups having 1 to 10 carbon atoms among thehydrocarbon groups exemplified as the monovalent organic group, and thelike.

Of these, hydrocarbon groups having 1 to 5 carbon atoms are preferred,alkyl groups having 1 to 5 carbon atoms are more preferred, a propylgroup and a butyl group are still more preferred, and a t-butyl group isparticularly preferred.

In a case where k is 0, p is preferably 2 or 3, and in a case where k is1, p is preferably 1.

Preferably q is an integer of 0 to 2, more preferably 0 or 1, and stillmore preferably 0.

The substituted or unsubstituted hydrocarbon group having 1 to 30 carbonatoms and having a valency of j which may be represented by X isexemplified by: substituted or unsubstituted hydrocarbon group having 1to 30 carbon atoms among substituted or unsubstituted hydrocarbon groupsexemplified as the monovalent organic group, and the like in a casewhere j is 1; and groups obtained by eliminating one hydrogen atom fromthe group described above, and the like in a case where j is 2.

Preferably j is 1.

X represents preferably a hydrogen atom, a substituted or unsubstitutedchain hydrocarbon group, or a substituted or unsubstituted aromatichydrocarbon group, more preferably a hydrogen atom, a substituted orunsubstituted divalent chain hydrocarbon group, or a substituted orunsubstituted monovalent aromatic hydrocarbon group, still morepreferably a hydrogen atom, an alkylene group, a hydroxy substitutedphenyl group, or an unsubstituted naphthyl group, and particularlypreferably a hydrogen atom, a trimethylene group, a 4-hydroxyphenylgroup, a 3,4-dihydroxyphenyl group, a 3,4,5-trihydroxyphenyl group, or a2-naphthyl group.

The compound (A) is preferably a compound represented by the followingformula (3), a compound represented by the following formula (4), or acompound represented by the following formula (5).

In the above formula (3), R represents a hydrogen atom or a monovalentorganic group having 1 to 30 carbon atoms; m is an integer of 4 to 12;Y, k, p and q are as defined in the above formula (1); and X is asdefined in the case where j in the above formula (2) is 1, wherein aplurality of Rs are identical or different, a plurality of Xs areidentical or different, a plurality of “k”s are identical or different,a plurality of “p”s are identical or different, and a plurality of “q”sare identical or different, and wherein in a case where Y is present ina plurality of number, a plurality of Ys are identical or different.

The lower limit of m is preferably 4, and more preferably 5 in light ofan improvement of the outgas inhibitory ability of the resist underlayerfilm formed from the composition for forming a resist underlayer film.The upper limit of m is preferably 8, more preferably 7, and still morepreferably 6 in light of an improvement of burying performances of thecomposition for forming a resist underlayer film.

In the above formula (4), R represents a hydrogen atom or a monovalentorganic group having 1 to 30 carbon atoms; n is 2 or 3; Y, k, p and qare as defined in the above formula (1); and X is as defined in the casewhere j in the above formula (2) is 2, wherein a plurality of Rs areidentical or different, a plurality of Xs are identical or different, aplurality of “k”s are identical or different, a plurality of “p”s areidentical or different, and a plurality of “q”s are identical ordifferent, and wherein in a case where Y is present in a plurality ofnumber, a plurality of Ys are identical or different.

In the above formula (5), R represents a hydrogen atom or a monovalentorganic group having 1 to 30 carbon atoms; Y, k, p and q are as definedin the above formula (1); and X is as defined in the case where j in theabove formula (2) is 2, wherein a plurality of Rs are identical ordifferent, a plurality of Xs are identical or different, a plurality of“k”s are identical or different, a plurality of “p”s are identical ordifferent, and a plurality of “q”s are identical or different, andwherein in a case where Y is present in a plurality of number, aplurality of Ys are identical or different.

Examples of the compound (A) include compounds represented by thefollowing formulae, and the like.

In the above formulae, Rs each independently represent a hydrogen atomor a monovalent organic group having 1 to 30 carbon atoms.

The lower limit of the molecular weight of the compound (A) ispreferably 500, more preferably 700, and still more preferably 1,000 inlight of an improvement of the flatness and the outgas inhibitoryability of the resist underlayer film formed. The upper limit of themolecular weight of the compound (A) is preferably 3,000, morepreferably 2,500, and still more preferably 2,200 in light of animprovement of the burying performances of the composition for forming aresist underlayer film and an improvement of the flatness of the resistunderlayer film.

The content of the compound (A) in the composition for forming a resistunderlayer film with respect to the total solid content is preferably noless than 80% by mass, more preferably no less than 90% by mass, andstill more preferably no less than 95% by mass.

(B) Organic Solvent

The organic solvent (B) is not particularly limited as long as it candissolve or disperse the compound (A), and the optional component(s)contained as desired.

The organic solvent (B) is exemplified by an alcohol solvent, an ethersolvent, a ketone organic solvent, an amide solvent, an ester organicsolvent, a hydrocarbon solvent, and the like.

Examples of the alcohol solvent include monohydric alcohol solventshaving 1 to 18 carbon atoms, polyhydric alcohol solvents having 2 to 18carbon atoms, polyhydric alcohol partial ether solvents having 3 to 19carbon atoms, and the like.

Examples of the ether solvent include:

dialkyl ether solvents such as diethyl ether, dipropyl ether and dibutylether;

cyclic ether solvents such as tetrahydrofuran and tetrahydropyran;

aromatic ring-containing ether solvents such as diphenyl ether andanisole; and the like.

Examples of the ketone solvent include:

chain ketone solvents such as acetone, methyl ethyl ketone, methyln-propyl ketone, methyl n-butyl ketone, diethyl ketone, methyl iso-butylketone, methyl n-pentyl ketone, ethyl n-butyl ketone, methyl n-hexylketone, di-iso-butyl ketone and trimethylnonanone;

cyclic ketone solvents such as cyclopentanone, cyclohexanone,cycloheptanone, cyclooctanone and methylcyclohexanone;

2,4-pentanedione, acetonyl acetone and acetophenone; and the like.

Examples of the amide solvent include:

cyclic amide solvents such as N,N′-dimethylimidazolidinone andN-methylpyrrolidone;

chain amide solvents such as N-methylformamide, N,N-dimethylformamide,N,N-diethylformamide, acetamide, N-methylacetamide,N,N-dimethylacetamide and N-methylpropionamide; and the like.

Examples of the ester solvent include: carboxylic acid ester solventssuch as monocarboxylic acid ester solvents, e.g., ethyl acetate andethyl lactate, and polyhydric carboxylic acid ester solvents, e.g.,diethyl malonate and diethyl phthalate; polyhydric alcohol partiallyetherified carboxylate solvents such as polyhydric alcohol partial etheracetate solvent, e.g., propylene glycol monomethyl ether acetate;lactone solvents such as butyrolactone and valerolactone; carbonatesolvents such as diethyl carbonate, ethylene carbonate and propylenecarbonate; and the like.

Examples of the hydrocarbon solvent include aliphatic hydrocarbonsolvents having 5 to 12 carbon atoms, aromatic hydrocarbon solventshaving 6 to 16 carbon atoms, and the like.

Of these, an ester solvent and a ketone solvent are preferred, apolyhydric alcohol partially etherified carboxylate solvent, acarboxylic acid ester solvent and a ketone solvent are more preferred, apolyhydric alcohol partial ether acetate solvent, a monocarboxylic acidester solvent and a cyclic ketone solvent are still more preferred,propylene glycol monomethyl ether acetate, ethyl lactate andcyclohexanone are particularly preferred, and propylene glycolmonomethyl ether acetate is more particularly preferred. The compositionfor forming a resist underlayer film may contain one, or two or moretypes of the organic solvent (B).

(C) Resin

The composition for forming a resist underlayer film may contain theresin (C) (except for those corresponding to the calixarene-basedcompound (A)). When the composition for forming a resist underlayer filmcontains the resin (C), the resist underlayer film formed from thecomposition for forming a resist underlayer film may exhibit improvedresistance to an organic solvent contained in a composition for forminga resist film, an interlayer or the like to be provided directly orindirectly on the resist underlayer film.

Although the resin (C) is not particularly limited as long as it is apolymer compound, at least one selected from the group consisting of anovolak resin, a resol resin, a styrene resin, an acenaphthylene resin,and a polyarylene resin is/are preferred. When the resin described aboveis used as the resin (C), the refractive index and the extinctioncoefficient of the resist underlayer film can be controlled so as togive an appropriate value. As a result, the rectangularity of thecross-sectional shape of the formed resist pattern may be improved. Thecomposition for forming a resist underlayer film may one, or two or moretypes of the resin (C).

The novolak resin is exemplified by a resin obtained by reacting one, ortwo or more of phenolic compound(s) selected from the group consistingof: phenols such as phenol, cresol, xylenol, resorcinol, bisphenol A,p-tert-butylphenol and p-octylphenol; naphthols such as α-naphthol,β-naphthol, 1,5-dihydroxynaphthalene and 2,7-dihydroxynaphthalene withan aldehyde or a divinyl compound using an acidic catalyst or the like.

The aldehyde is exemplified by: aldehydes such as formaldehyde; aldehydesources such as paraformaldehyde and trioxane; and the like.

The divinyl compound is exemplified by divinylbenzene,dicyclopentadiene, tetrahydroindene, 4-vinylcyclohexene,5-vinylnorborn-2-ene, α-pinene, β-pinene, limonene,5-vinylnorbornadiene, and the like.

The resol resin is exemplified by: a resin obtained by reacting thephenolic compound with the aldehyde using an alkaline catalyst; and thelike.

The styrene resin is exemplified by polystyrene; styrene copolymers suchas styrene-α-methyl styrene copolymer and styrene-butadiene copolymer;and the like.

The acenaphthylene resin is exemplified by: a resin obtained bypolymerizing a compound having an acenaphthylene skeleton throughradical polymerization, anionic polymerization, cationic polymerizationor the like, in an appropriate polymerization system such as bulkpolymerization and solution polymerization; and the like. In addition,the acenaphthylene resin can be obtained by, for example, reacting apolymer of a compound having an acenaphthylene skeleton withparaformaldehyde under an acidic condition, as described in paragraphs[0008] to [0031] of Japanese Unexamined Patent Application, PublicationNo. 2002-296789.

The polyarylene resin is exemplified by polyarylene ether, polyarylenesulfide, polyarylene ether sulfone, polyarylene ether ketone, and thelike.

The resin (C) preferably includes a naphthalene ring. When the resin (C)has the naphthalene skeleton, the refractive index and the extinctioncoefficient of the resist underlayer film can be controlled so as togive a more appropriate value, and as a result, the rectangularity ofthe cross-sectional shape of the formed resist pattern may be furtherimproved. In addition, the resin (C) preferably includes a groupincluding a carbon-carbon triple bond. When the resin (C) includes theabove-described group, etching resistance and flexural resistance of theresist underlayer film formed may be improved. Examples of the grouphaving a carbon-carbon triple bond include an ethynyl group, a propargylgroup, and the like.

The resin (C) preferably includes a crosslinkable group. When the resin(C) includes the crosslinkable group, the strength of the resistunderlayer film formed can be improved owing to the crosslinking betweenthe resins (C) or between the resin (C) and the compound (A).

It is also preferred that the resin (C) does not substantially include acrosslinkable group. When the resin (C) does not substantially includethe crosslinkable group, film shrinkage that occurs in the formation ofthe resist underlayer film can be inhibited, and as a result, theflatness of the resist underlayer film formed can be improved.

The weight average molecular weight (Mw) of the resin (C) is preferablyno less than 2,000 and no greater than 8,000, and more preferably noless than 3,000 and no greater than 7,000. When the Mw of the resin (C)falls within the above range, the solvent resistance of the resistunderlayer film formed from the composition for forming a resistunderlayer film can be further improved.

The ratio (Mw/Mn) of the weight average molecular weight to the numberaverage molecular weight (Mn) of the resin (C) is preferably 1 to 5,more preferably 1 to 3, and still more preferably 1 to 2.5.

The content of the resin (C) with respect to 100 parts by mass of thecompound (A) is preferably no less than 5 parts by mass and no greaterthan 1,000 parts by mass, more preferably no less than 10 parts by massand no greater than 700 parts by mass, and still more preferably no lessthan 30 parts by mass and no greater than 400 parts by mass. When thecontent of the resin (C) falls within the above range, the solventresistance of the resist underlayer film formed from the composition forforming a resist underlayer film can be further improved.

Oher Optional Component

The composition for forming a resist underlayer film may contain otheroptional component(s) in addition to the components (A) to (C). Theother optional component is exemplified by an acid generating agent, acrosslinking agent, a surfactant, and the like. These other optionalcomponents each may be used either alone, or in combination of two ormore types thereof.

Acid Generating Agent

The acid generating agent is a component that generates an acid upon anexposure or heating. When the composition for forming a resistunderlayer film contains the acid generating agent, a crosslinkingreaction between the compounds (A), between the compounds (C) or betweenthe compounds (A) and the resin (C) can be allowed to proceed atcomparatively low temperatures including normal temperatures.

An acid generating agent that generates an acid upon an exposure(hereinafter, may be also referred to as “photoacid generating agent”)is exemplified by those described in paragraphs [0077] to [0081] of theJapanese Unexamined Patent Application, Publication No. 2004-168748.

Moreover, an acid generating agent that generates an acid upon heating(hereinafter, may be also referred to as “thermal acid generatingagent”) is exemplified by 2,4,4,6-tetrabromocyclohexadienone, benzointosylate, 2-nitrobenzyl tosylate, alkylsulfonates, and the like inaddition to the onium salt acid generating agents exemplified as thephotoacid generating agent described above.

Of these acid generating agents, thermal acid generating agents arepreferred, onium salt acid generating agents are more preferred,iodonium salt acid generating agents are still more preferred,diphenyliodonium trifluoromethanesulfonate, diphenyliodoniumnonafluoro-n-butanesulfonate, diphenyliodonium pyrenesulfonate,diphenyliodonium n-dodecylbenzenesulfonate, diphenyliodonium10-camphorsulfonate, diphenyliodonium naphthalenesulfonate,bis(4-t-butylphenyl)iodonium trifluoromethanesulfonate,bis(4-t-butylphenyl)iodonium nonafluoro-n-butanesulfonate,bis(4-t-butylphenyl)iodonium n-dodecylbenzenesulfonate,bis(4-t-butylphenyl)iodonium 10-camphorsulfonate andbis(4-t-butylphenyl)iodonium naphthalenesulfonate are particularlypreferred, and bis(4-t-butylphenyl)iodonium nonafluoro-n-butanesulfonateis more particularly preferred.

The content of the acid generating agent with respect to 100 parts bymass of the compound (A) is preferably no greater than 5,000 parts bymass, more preferably 0.1 parts by mass to 1,000 parts by mass, andstill more preferably 10 parts by mass to 300 parts by mass. One, or twoor more types of the acid generating agent may be used. Moreover, thephotoacid generating agent and the thermal acid generating agent may beused in combination as the acid generating agent.

Crosslinking Agent

The crosslinking agent is a compound that includes a crosslinkable group(except for those corresponding to the compound (A) and the resin (C)).When the composition for forming a resist underlayer film contains thecrosslinking agent, the crosslinking between the compounds (A), betweenthe compounds (C) or between the compounds (A) and the resin (C) can beachieved more effectively.

The crosslinking agent preferably includes two or more crosslinkablegroups.

Examples of the crosslinking agent include: methoxymethylated melaminessuch as hexakis(methoxymethyl)melamine; methoxymethylated glycolurilssuch as tetrakis(methoxymethyl)glycoluril; and the like. Of these,methoxymethylated glycolurils are preferred, and1,3,4,6-tetrakis(methoxymethyl)glycoluril is more preferred.

The content of the crosslinking agent with respect to 100 parts by massof the compound (A) is preferably no greater than 1,000 parts by mass,more preferably 5 parts by mass to 700 parts by mass, and still morepreferably 30 parts by mass to 500 parts by mass. One or two or moretypes of the crosslinking agent may be used.

Surfactant

The surfactant is a component that exhibits the effects of improvingapplication properties, striation, wettability, developability and thelike. The content of the surfactant with respect to 100 parts by mass ofthe compound (A) is preferably no greater than 15 parts by mass, andmore preferably no greater than 10 parts by mass. One or two or moretypes of the surfactant may be used.

Preparation Method of Composition for Forming Resist Underlayer Film

The composition for forming a resist underlayer film may be prepared,for example, by mixing the compound (A) and the organic solvent (B), aswell as the optional component(s) which may be contained as needed at apredetermined ratio. The composition for forming a resist underlayerfilm is preferably filtered through a filter of about 0.1 μm, forexample, after the mixing. The solid content concentration of thecomposition for forming a resist underlayer film is preferably 0.1% bymass to 50% by mass, more preferably 0.5% by mass to 30% by mass, andstill more preferably 1% by mass to 20% by mass. The concentration ofthe compound (A) in the composition for forming a resist underlayer filmis preferably 0.1% by mass to 30% by mass, more preferably 0.5% by massto 20% by mass, and still more preferably 1% by mass to 15% by mass.

The viscosity of the composition for forming a resist underlayer film ata solid content concentration of 20% by mass is preferably no less than1 cps and no greater than 5 cps, and more preferably no less than 1 cpsand no greater than 3 cps. When the value of the viscosity of thecomposition for forming a resist underlayer film falls within the aboverange, burying performances may be improved, and the flatness of theresist underlayer film formed may be improved.

Pattern-Forming Method

A pattern-forming method according another embodiment of the presentinvention includes in the following order of:

providing a resist underlayer film directly or indirectly on a substrate(hereinafter, may be also referred to as “resist underlayerfilm-providing step”);

forming a resist pattern directly or indirectly on the resist underlayerfilm (hereinafter, may be also referred to as “resist pattern-formingstep”);

forming a pattern on the substrate through dry etching of the resistunderlayer film, the substrate, or both the resist underlayer film andthe substrate using the resist pattern as a mask (hereinafter, may bealso referred to as “substrate pattern-forming step”); and

removing the resist underlayer film remaining on the substrate using abasic solution (hereinafter, may be also referred to as “removingstep”),

wherein the method further includes the step of subjecting the resistunderlayer film to heating or an acid treatment before the removingstep, and

wherein the resist underlayer film is provided using the composition forforming a resist underlayer film according to the embodiment of thepresent invention.

The substrate is preferably stepped.

Moreover, the pattern-forming method preferably includes after theresist underlayer film-providing step and before the resistpattern-forming step:

providing an intermediate layer directly or indirectly on the resistunderlayer film (hereinafter, may be also referred to as “intermediatelayer-providing step”), and

the intermediate layer is preferably further dry etched in the substratepattern-forming step.

According to the pattern-forming method, due to using the compositionfor forming a resist underlayer film described above, a resistunderlayer film superior in flatness, solvent resistance andoutgas-inhibitory ability can be formed, and in turn, a favorablepattern can be formed. In addition, the pattern-forming method can bealso suitably applied to stepped substrates and substrates having aplurality of types of trenches; on such substrates, a resist underlayerfilm superior in flatness can be formed, and in turn, a favorablepattern can be formed.

Moreover, according to the pattern-forming method, since the resistunderlayer film is removed with a basic solution after the formation ofthe pattern through etching, the resist underlayer film can be easilyremoved while minimizing the influence exerted on the substrate.

Hereinafter, each step will be explained.

Resist Underlayer Film-Providing Step

In this step, a resist underlayer film is provided directly orindirectly on a substrate using the composition for forming a resistunderlayer film.

The substrate is exemplified by a silicon wafer, a wafer covered withaluminum, and the like.

As described above, in the pattern-forming method, the steppedsubstrates, the substrates having a plurality of types of trenches andthe like can be also suitably used, and a resist underlayer filmsuperior in flatness can be formed.

As a substrate having a plurality of types of trenches, a substratehaving trenches differing from one another in terms of an aspect ratiocan be also suitably used, for example. A substrate that involvesvarious values of the aspect ratio may also be used; for example, theratio of the maximum value to the minimum value of the aspect ratios ofthe trenches of the substrate is preferably no less than 3, morepreferably no less than 5, still more preferably no less than 10, andparticularly preferably no less than 15.

The procedure for applying the composition for forming a resistunderlayer film to the substrate is not particularly limited, andapplying the composition may be carried out by an appropriate proceduresuch as, for example, spin-coating, cast coating and roll coating.

Moreover, after applying the composition for forming a resist underlayerfilm, heating is typically executed for the purpose of removing thesolvent from the coating film.

The film thickness of the resist underlayer film provided is preferably10 nm to 5 μm, and more preferably 30 nm to 0.5 μm.

Intermediate Layer-Providing Step

In this step, an interlayer is provided directly or indirectly on theresist underlayer film provided in the resist underlayer film-providingstep. The intermediate layer has functions exhibited by the resistunderlayer film and/or the resist film in the resist pattern formationfor the purpose of reinforcing the abovementioned functions, or hasfunctions not exhibited by the resist underlayer film and/or the resistfilm in the resist pattern formation for the purpose of imparting theunexhibited functions. For example, in a case where an antireflectivefilm is provided as the intermediate layer, a reflection-preventivefunction of the resist underlayer film can be reinforced.

The intermediate layer may be provided using an organic compound or aninorganic oxide. Examples of the organic compound include materialscommercially available from Brewer Science, Inc. under the trade name“DUV-42”, “DUV-44”, “ARC-28”, “ARC-29” and the like, and materialscommercially available from Rohm & Haas Company under the trade name“AR-3”, “AR-19” and the like, etc. Moreover, examples of the inorganicoxide include materials commercially available from JSR Corporationunder the trade name “NFC SOG” series, and polysiloxanes, titaniumoxide, oxidized alumina, tungsten oxide, or the like which are formed bya CVD process may be used.

The procedure for providing the intermediate layer is exemplified by,but not particularly limited to, a coating procedure, a CVD process, andthe like. Of these, the coating procedure is preferred. In a case wherethe coating procedure is employed, the intermediate layer can beprovided consecutively after providing the resist underlayer film.

Moreover, although the film thickness of the intermediate layer is notparticularly limited and appropriately selected in accordance with thefunctions required for the intermediate layer, the film thickness of theintermediate layer is preferably 10 nm to 3 m, and more preferably 20 nmto 0.3 μm.

Resist Pattern-Forming Step

In this step, a resist pattern is formed directly or indirectly on theresist underlayer film. This step is exemplified by a procedureinvolving photolithography, and the like. Hereinafter, this procedurewill be specifically explained.

An exemplary procedure involving photolithography includes:

providing a resist film directly or indirectly on the resist underlayerfilm using a resist composition (hereinafter, may be also referred to as“resist film-providing step”);

exposing the resist film (hereinafter, may be also referred to as“exposure step”); and

developing the resist film exposed (hereinafter, may be also referred toas “development step”).

Resist Film-Providing Step

In this step, a resist film is provided directly or indirectly on theresist underlayer film using a resist composition. Specifically, afterthe resist composition is applied such that the resulting resist filmhas a predetermined film thickness, prebaking is executed to evaporatethe solvent in the coating film, whereby the resist film is provided.

The resist composition is exemplified by: a positive type or negativetype chemical amplification resist composition that contains a photoacidgenerating agent; a positive type resist composition that contains analkali-soluble resin and a quinone diazide photosensitizing agent; anegative type resist composition that contains an alkali-soluble resinand a crosslinking agent; and the like.

The solid content concentration of the resist composition is preferably5 to 50% by mass. In addition, the resist composition is preferablyprepared after filtration thereof through a filter having a pore size ofabout 0.2 μm. It is to be noted that in this step, a commerciallyavailable resist composition may be directly used.

The procedure for applying the resist composition is not particularlylimited, and applying the resist composition may be carried out by anappropriate procedure such as, for example, spin-coating, cast coating,roll coating.

Moreover, the prebaking temperature may be appropriately selected inaccordance with the type of the resist composition used and the like,but is preferably 30° C. to 200° C., and more preferably 50° C. to 150°C.

Exposure Step

In this step, the resist film provided in the resist film-providing stepis exposed. The exposure is executed through a certain mask pattern, anda liquid immersion liquid, as needed.

The exposure light may be appropriately selected in accordance with thetype of the photoacid generating agent used in the resist composition,from e.g., electromagnetic waves such as visible light rays, ultravioletrays, far ultraviolet rays, X-rays and γ-rays; particle rays such aselectron beams, molecular beams, ion beams and α-rays; and the like.However, the far ultraviolet rays are preferred; a KrF excimer laserbeam (248 nm), an ArF excimer laser beam (193 nm), an F₂ excimer laserbeam (wavelength: 157 nm), a Kr₂ excimer laser beam (wavelength: 147nm), an ArKr excimer laser beam (wavelength: 134 nm), an extremeultraviolet ray (wavelength: 13 nm, etc.) are more preferred; and an ArFexcimer laser beam is still more preferred.

In order to improve the resolution, the pattern profile, thedevelopability, etc. of the formed resist pattern, post-baking may beexecuted after the exposure. The temperature of the post-baking may beappropriately adjusted in accordance with the type of the resistcomposition used and the like, but is preferably 50° C. to 200° C., andmore preferably 70° C. to 150° C.

Development Step

In this step, the resist film exposed in the exposure step is developed.

The developer solution which may be used in the development may beappropriately selected in accordance with the type of the resistcomposition used. For a development with an alkali, specific examples ofthe developer solution includes: aqueous alkaline solutions such assodium hydroxide, potassium hydroxide, sodium carbonate, sodiumsilicate, sodium metasilicate, ammonia, ethylamine, n-propylamine,diethylamine, di-n-propylamine, triethylamine, methyldiethylamine,dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide,tetraethylammonium hydroxide, pyrrole, piperidine, choline,1,8-diazabicyclo[5.4.0]-7-undecene and 1,5-diazabicyclo[4.3.0]-5-nonene;and the like. It is to be noted that in a case where theinterlayer-providing step is executed to provide the intermediate layer,the influence of these aqueous alkaline solutions on the resistunderlayer film can be minimized.

An appropriate amount of water soluble organic solvent, for example, analcohol such as methanol and ethanol, and/or a surfactant may be addedto these aqueous alkaline solutions.

Moreover, an organic solvent-containing developer solution may be usedas the developer solution. Examples of the organic solvent includeesters, ketones, ethers, alcohols, amides, hydrocarbons, and the like.The development with an organic solvent has a minor influence on theresist underlayer film.

After the development with the developer solution, washing and dryingare executed, whereby a predetermined resist pattern is formed.

Moreover, a procedure involving nanoimprinting, a procedure involvingthe use of a directed self-assembling composition, and the like may bealso used as the procedure for executing the resist pattern-forming stepin place of the procedure involving photolithography described above.

Substrate Pattern-Forming Step

In this step, a pattern is formed on the substrate through dry etchingof the resist underlayer film, the substrate, or both the resistunderlayer film and the substrate using the resist pattern as a mask. Itis to be noted that in a case where the intermediate layer is provided,the intermediate layer is further dry etched.

The dry etching may be executed using a well-known dry etchingapparatus. In addition, depending on the elemental composition of asubstance to be etched, the following gases may be used as a sauce gasin the dry etching: oxygen atom-containing gases such as O₂, CO and CO₂;inert gases such as He, N₂ and Ar; chlorine-based gases such as Cl₂ andBCl₃; fluorine-based gases such as CHF₃ and CF₄; and other gas such asH₂ and NH₃. It is to be noted that these gases may also be used inmixture.

Step of Subjecting Resist Underlayer Film to Heating or Acid Treatment

The pattern-forming method according to the embodiment of the presentinvention further includes subjecting the resist underlayer film toheating or an acid treatment before the removing step described later.According to this step, a part or all of organic groups substituting thehydrogen atom of phenolic hydroxyl groups included in the compound (A)constituting the resist underlayer film are dissociated to generate aphenolic hydroxyl group. Due to the phenolic hydroxyl group being thusgenerated in the compound (A), the resist underlayer film can be easilyremoved with a basic solution.

The procedure for allowing a part or all of the organic groups to bedissociated is preferably heating of the resist underlayer film. Thetemperature of the heating is preferably 100° C. to 330° C., morepreferably 200° C. to 320° C., and still more preferably 240° C. to 300°C. In addition, the time period for the heating is preferably 10 sec to600 sec, and more preferably 30 sec to 240 sec. Furthermore, the oxygenconcentration in the heating is preferably no less than 5% by volume,and still more preferably no less than 20% by volume.

It is to be noted that in a case where the composition for forming aresist underlayer film contains a thermal acid generating agent or thelike, dissociation of the organic group is catalyzed by an acidgenerated from the thermal acid generating agent or the like upon theheating. Consequently, the dissociation of the organic group can beachieved at lower temperatures.

In addition to the procedure involving heating, the procedure forallowing the organic group to be dissociated is also exemplified by aprocedure involving treating the resist underlayer film with an acid.The procedure for treating the resist underlayer film with an acid isexemplified by: a procedure involving washing with an acid; a procedureinvolving irradiating the resist underlayer film with light in a casewhere the composition for forming a resist underlayer film contains aphotoacid generating agent or the like; and the like.

The time point when the step of subjecting the resist underlayer film toheating or an acid treatment is executed is not particularly limited aslong as this step is executed before the removing step in thepattern-forming method. For example, this step may be executed at anytime point described in the following, or a combination of two or morethereof: after the resist underlayer film-providing step and before theresist pattern-forming step (i.e., before the resist underlayerfilm-providing step and after the intermediate layer-providing step, orafter the intermediate layer-providing step and before the resistpattern-forming step); after the resist pattern-forming step and beforethe substrate pattern-forming step; after the substrate pattern-formingstep; or concurrently with the resist underlayer film-providing step,the resist pattern-forming step or the substrate pattern-forming step.Of these, in light of ease of operation, this step is executedpreferably: concurrently with the resist underlayer film-providing step,in other words, in the heating for providing a resist underlayer film orthe like; or after the substrate pattern-forming step, in other words,using the resist underlayer film obtained after the etching step.

Removing Step

In the removing step, the resist underlayer film on the substrate isremoved with a basic solution.

Although the basic solution used in this step is not particularlylimited as long as the solution is basic, examples thereof include basicaqueous solutions of sodium hydroxide, potassium hydroxide, sodiumcarbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine,n-propylamine, diethylamine, di-n-propylamine, triethylamine,methyldiethylamine, dimethylethanolamine, triethanolamine,tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide,pyrrole, piperidine, choline, 1,8-diazabicyclo[5.4.0]-7-undecene,1,5-diazabicyclo[4.3.0]-5-nonene, or the like. Of these, an aqueous TMAHsolution is preferred. Alternatively, an appropriate amount of a watersoluble organic solvent, for example, an alcohol such as methanol andethanol, and/or a surfactant may be added to these basic aqueoussolutions. Moreover, solutions containing an organic solvent in additionto or instead of water may be used as long as the solutions are basic.

The pH of the basic solution is, for example, preferably no less than7.5, and still more preferably no less than 8. When the pH is less than7.5, the resist underlayer film is less likely to be sufficientlyremoved.

The procedure for removing the resist underlayer film with the basicsolution is not particularly limited as long as the resist underlayerfilm is brought into contact with the basic solution for a certain timeperiod; examples thereof include: a procedure that involves immersingthe patterned substrate in the basic solution; a procedure that involvesspraying the basic solution; a procedure that involves coating the basicsolution; and the like. It is to be noted that the time period for theimmersion in the procedure that involves immersing is, for example, 0.2min to 30 min. After the completion of any of these procedures, thesubstrate is preferably washed with water, and dried.

According to the pattern-forming method, the resist underlayer film isremoved with the basic solution after forming a pattern on a substrateby etching, as described above. Accordingly, the resist underlayer filmcan be easily removed while minimizing the influence exerted on thesubstrate. In particular, according to the pattern-forming method, evenwhen a low dielectric material which is likely to be affected by ashingor the like is used as the substrate, the resist underlayer film can beremoved while minimizing the influence on the substrate.

EXAMPLES

Hereinafter, the present invention is explained in detail by way ofExamples, but the present invention is not in any way limited to theseExamples. Measuring methods for various types of physical properties areshown below.

Confirmation of Structure of Compound (A)

The structure of the compound (A) was confirmed based on the molecularweight as determined by means of MALDI-TOF-MS (SHIMAZU/KRATOSmatrix-assisted laser desorption/ionization time-of-flight massspectrometry apparatus KOMPACT MALDI IV tDE, manufactured by ShimadzuCorporation), an infrared absorption spectrum (IR) recorded on a Fouriertransform infrared spectrometer (FT-IR) (model 420, manufactured byJASCO Corporation), and a ¹H-NMR spectrum recorded on a nuclear magneticresonance apparatus (model JNM-ECA-500, manufactured by JEOL, Ltd.) witha solvent for measurement of DMSO-d₆.

Mw of Resin (C)

The Mw of the resin (C) was determined by gel permeation chromatographyusing GPC columns (G2000HXL×2 and G3000HXL×1, manufactured by TosohCorporation), a “differential refractometer” as a detector, andmono-dispersed polystyrene as a standard under an analytical conditioninvolving a flow rate of 1.0 mL/min, an elution solvent oftetrahydrofuran, and a column temperature of 40° C.

Synthesis of Compound (A) Synthesis Example 1 Synthesis of Compound(A-1)

(1-1)

Into a 1,000 mL three-neck eggplant shaped flask were charged 35 g ofresorcinol, 39 g of p-hydroxybenzaldehyde and 450 g of ethanol, anddissolution was completed at room temperature under a nitrogenatmosphere. To the resulting solution was added dropwise 95.6 g ofconcentrated hydrochloric acid over 1 hour at the solution temperatureof 40° C., then the solution temperature was elevated to 80° C., and themixture was aged for 11 hrs. After the aging, the flask was cooled untilthe solution temperature dropped to room temperature. Thereafter,filtration was carried out in order to remove the ethanol solution,whereby a reddish brown solid matter deposited was recovered. Thereddish brown solid matter was washed with a flowing mixed solution ofmethanol/water (each 300 g), and then dried under reduced pressure at60° C. overnight to obtain 43.6 g of a precursor X having phenolichydroxyl groups as a pink solid matter. It was confirmed by ¹H-NMR thatthe intended precursor X was obtained.

(1-2)

Next, in a 500 mL round-bottom flask, 10.0 g of the precursor X obtainedin (1-1) described above was dissolved in 200 mL ofN,N-dimethylacetamide under a nitrogen atmosphere with stirring by meansof a magnetic stirrer. Under the stirring, 21.4 g of2-chloromethylstyrene was added to the resulting solution, then 28.4 gof potassium carbonate was further added thereto, and the reaction wasallowed to proceed at 80° C. for 18 hrs. After completing the reaction,the reaction solution was added to 2 L of water to which 14 mL of aceticacid was added. The supernatant liquid was removed. The residual highlyviscous matter was dissolved in a minimum amount of acetone, and thesolution was charged into 500 mL of water to permit reprecipitation. Theresulting highly viscous matter was dried under reduced pressure at 65°C. overnight to obtain 12.5 g of a compound (A-1) as a brown solid.

Synthesis Examples 2 to 24 Synthesis of Compounds (A-2) to (A-24)

Compounds (A-2) to (A-24) (compounds represented by the followingformulae (A-2) to (A-24)) were synthesized in a similar manner toSynthesis Example 1 except that the phenolic compound, the aldehydecompound, and the compound used for substitution of the hydrogen atomincluded in the phenolic hydroxyl group were appropriately changed.

Synthesis Example 25 Synthesis of Compound (A-25)

Into a reaction apparatus equipped with a condenser, a thermometer and astirrer were charged 100 parts by mass of resorcinol and 200 parts bymass of ethanol, and 68 parts by mass of hydrochloric acid was furtheradded thereto. This solution was cooled to 5° C. with stirring, 45 partsby mass of 50% by mass aqueous 1,5-pentanedial solution was slowly addeddropwise. Thereafter, the mixture was heated at 80° C. for 48 hrs,whereby a yellow turbid suspension was obtained. After the suspensionwas poured into methanol, precipitates were recovered by filtration, andwashed three times with methanol. The obtained precipitates were driedunder reduced pressure at room temperature for 24 hrs, whereby a lightyellow solid was obtained as a powder. Next, to 100 parts by mass of theobtained light yellow solid were added 23 parts by mass oftetrabutylammonium bromide and 350 parts by mass of anhydrous pyridine,and the mixture was stirred for 1 hour. Thereafter, 185 parts by mass ofdi-t-butyl dicarbonate was slowly added, and the mixture was stirred atroom temperature for 48 hrs. After completing the reaction, the reactionliquid was poured into 300 mL of a 3% by mass aqueous oxalic acidsolution to permit deposition of a solid. Thereafter, the resultingsolid was dissolved in methylene chloride, then washed three times with100 mL of a 3% by mass aqueous oxalic acid solution, and thereafterwashed with 100 mL of water. After removing the water layer, the organiclayer was dried over anhydrous magnesium sulfate. Thereafter,purification by silica gel column chromatography using hexane: ethylacetate (1:1 (volume ratio)) as an eluent was carried out to obtain acompound (A-25) (a compound represented by the following formula(A-25)).

With respect to the compounds (A-1) to (A-25) obtained in SynthesisExamples 1 to 25 described above, Rs in the following formulae representa hydrogen atom or a group represented by the corresponding formula;and * denotes a binding site with respect to the oxygen atom. Inaddition, ¹H-NMR analysis of each compound (A) was carried out, andconsequently it was found that a ratio of the number of substitutedphenolic hydroxyl groups to the number of unsubstituted phenolichydroxyl groups (substituted phenolic hydroxyl group/unsubstitutedphenolic hydroxyl group) (hereinafter, may be also referred to as“number ratio “a””) was as shown in Table 1 below. More specifically, ina case where the number ratio “a” is x/y, wherein a sum of x and y isequal to 100, x (%) of Rs included in each compound (A) represent thegroup represented by the following formula as R, whereas y (%) of Rsrepresent a hydrogen atom.

TABLE 1 Number ratio “a” (number of (A) substituted phenolic hydroxylgroups/number Compound of unsubstituted phenolic hydroxyl groups) A-170/30 A-2 80/20 A-3 90/10 A-4 80/20 A-5 70/30 A-6 80/20 A-7 80/20 A-880/20 A-9 70/30 A-10 80/20 A-11 80/20 A-12 80/20 A-13 70/30 A-14 80/20A-15 70/30 A-16 80/20 A-17 75/25 A-18 80/20 A-19 80/20 A-20 75/25 A-2170/30 A-22 80/20 A-23 80/20 A-24 80/20 A-25 50/50

The calixarene (compound (a-1)) used in the composition for forming aresist underlayer film according to Comparative Example is shown below.

Synthesis of Resin (C) Synthesis Example 26 Synthesis of Resin (C-1)

Into a separable flask equipped with a thermometer were charged 10 partsby mass of 2,7-naphthalenediol/formaldehyde condensate (a resinincluding hydroxy groups), 10 parts by mass of propargyl bromide, 10parts by mass of triethylamine and 40 parts by mass of tetrahydrofuran,and the reaction was allowed to proceed at 50° C. for 12 hrs withstirring. After completing the reaction, the reaction solution wascooled to 30° C. or below by water-cooling. After the cooling, thereaction solution was charged into a large amount of n-heptane.Thereafter, the deposited solid was separated by decantation, and washedwith a large amount of n-heptane. Subsequently, the solid was dissolvedin methyl isobutyl ketone, and washed sequentially with a 1% by massaqueous oxalic acid solution and pure water to eliminate residualtriethylamine. Then, the resulting organic layer was concentrated, anddried at 50° C. for 17 hrs, whereby a resin (C-1) was obtained. Theresin (C-1) had an Mw of 4,500, and the percentage of the propargylgroup introduced into the resin (C-1) was 90% with respect to the totalhydroxy groups.

Preparation of Composition for Forming Resist Underlayer Film

Each component used in the preparation of compositions for forming aresist underlayer film is shown below.

(B) Organic Solvent

B-1: propylene glycol monomethyl ether acetate

B-2: propylene glycol monomethyl ether

(D) Acid Generating Agent

D-1: bis(4-t-butylphenyl)iodonium nonafluoro-n-butanesulfonate (acompound represented by the following formula (D-1))

(E) Crosslinking Agent

E-1: 1,3,4,6-tetrakis(methoxymethyl)glycoluril (a compound representedby the following formula (E-1))

Example 1 Preparation of Composition for Forming Resist Underlayer Film(U-1)

A solution was prepared by dissolving 5 parts by mass of the resin (A-1)obtained in Synthesis Example 1 in 95 parts by mass of propylene glycolmonomethyl acetate (organic solvent (B-1)). Thereafter, this solutionwas filtered through a membrane filter having a pore size of 0.1 m toprepare a composition for forming a resist underlayer film (U-1).

Examples 2 to 28 and Comparative Example 1 Preparation of Compositionsfor Forming Resist Underlayer Film (U-2) to (U-28) and (CU-1)

Compositions for forming a resist underlayer film (U-2) to (U-28) and(CU-1) were prepared in a similar manner to Example 1 except that thetype and the content of the components used were as shown in Tables 2-1and 2-2 below. It is to be noted that “−” in Tables 2-1 and 2-2indicates that the corresponding component was not used.

TABLE 2-1 (D) Acid (E) Cross- Composition (B) Organic generating linkingfor forming (A) Component solvent (C) Resin agent agent resist contentcontent content content content underlayer (parts by (parts by (parts by(parts by (parts by film type mass) type mass) type mass) type mass)type mass) Example 1 U-1 A-1 5 B-1 95 — — — — — — Example 2 U-2 A-3 5B-1 95 — — — — — — Example 3 U-3 A-6 2.5 B-1 95 C-1 2.5 — — — — Example4 U-4 A-7 5 B-1 95 — — — — — — Example 5 U-5 A-8 5 B-1 95 — — — — — —Example 6 U-6 A-11 5 B-1 95 — — — — — — Example 7 U-7 A-12 5 B-1 95 — —— — — — Example 8 U-8 A-13 5 B-1 95 — — — — — — Example 9 U-9 A-15 5 B-195 — — — — — — Example 10 U-10 A-17 5 B-1 95 — — — — — — Example 11 U-11A-20 2.5 B-1 95 C-1 2.5 — — — — Example 12 U-12 A-2 2.5 B-1 95 C-1 2.5 —— — — Example 13 U-13 A-4 2.5 B-1 95 C-1 2.5 — — — — Example 14 U-14 A-55 B-1 95 — — D-1 5 E-1 10 Example 15 U-15 A-9 2.5 B-1 95 C-1 2.5 — — — —Example 16 U-16 A-10 5 B-1 95 — — D-1 5 E-1 10 Example 17 U-17 A-14 2.5B-1 95 C-1 2.5 — — — — Example 18 U-18 A-24 2.5 B-1 95 C-1 2.5 — — — —Example 19 U-19 A-1/A-16 2.5/2.5 B-1 95 — — — — — — Example 20 U-20A-17/A-18 2.5/2.5 B-1 95 — — — — — —

TABLE 2-2 (D) Acid (E) Cross- Composition (B) Organic generating linkingfor forming (A) Component solvent (C) Resin agent agent resist contentcontent content content content underlayer (parts by (parts by (parts by(parts by (parts by film type mass) type mass) type mass) type mass)type mass) Example 21 U-21 A-14/A-20 1.25/1.25 B-1 95 C-1 2.5 — — — —Example 22 U-22 A-22 2.5 B-1 95 C-1 2.5 — — — — Example 23 U-23 A-21 2.5B-1 95 C-1 2.5 — — — — Example 24 U-24 A-23 5 B-1 95 — — — — — — Example25 U-25 A-19 2.5 B-1 95 C-1 2.5 — — — — Example 26 U-26 A-25 5 B-1 95 —— — — — — Example 27 U-27 A-14 5 B-1 95 — — — — — — Example 28 U-28 A-245 B-1 95 — — — — — — Comparative CU-1 a-1 5 B-2 95 — — — — — — Example 1

Formation of Resist Underlayer Film Examples 1 to 28 and ComparativeExample 1

Each composition for forming a resist underlayer film prepared inExamples and Comparative Example described above was applied on asilicon wafer (substrate) by way of a spin coating procedure.Thereafter, baking was carried out at 250° C. for 60 sec under anambient air atmosphere (however, in Example 25, baking was carried outat 250° C. for 60 sec, and further at 350° C. for 60 sec) to form aresist underlayer film having a film thickness of 200 nm, whereby each“resist underlayer film-carrying substrate” in which the resistunderlayer film is formed on the substrate was obtained.

Evaluations

The compositions for forming a resist underlayer film obtained above orthe resist underlayer film-carrying substrates obtained therefrom wereevaluated for the following items in accordance with the followingmethods. The results of the evaluations are shown in Tables 3-1 and 3-2.

Solubility in PGMEA

Each composition for forming a resist underlayer film obtained above wasadded to a PGMEA (propylene glycol monomethyl ether acetate) solvent toexecute a solubility test. The solubility in PGMEA was evaluated to be“A” (favorable) in a case where the composition for forming a resistunderlayer film was dissolved in the solution without any turbidnessand/or deposited matter, and to be “B” (unfavorable) in a case whereturbidness and/or deposited matter were/was found in the solution.

Etching Resistance

The resist underlayer film of the resist underlayer film-carryingsubstrate obtained above was etched using an etching apparatus (tradename “EXAM”, manufactured by Shinko Seiki Co., Ltd.), with CF₄/Ar/O₂(CF₄: 40 mL/min, Ar: 20 mL/min, O₂: 5 mL/min; pressure: 20 Pa; RF power:200 W; treatment time period: 40 sec; and temperature: 15° C.). Then,the film thickness of the resist underlayer film was measured before andafter the etching treatment, followed by calculation of an etching rate,and the etching resistance was evaluated based on the etching rate. Itis to be noted that the calculation of the etching rate was carried outby using as a reference resist underlayer film, a resist underlayer filmformed from a composition for forming a resist underlayer film (tradename “NFC CTL53”, manufactured by JSR Corporation). The etchingresistance was evaluated to be “S” (superior) in a case where animprovement by greater than 10% was found as compared with the referenceresist underlayer film (i.e., the etching rate being less than 90%), tobe “A” (favorable) in a case where the etching rate was no less than 90%and less than 110%, and to be “B” (somewhat favorable) in a case wherethe etching rate was no less than 110%.

Solvent Resistance

Each resist underlayer film-carrying substrate obtained above wasimmersed in cyclohexanone at room temperature for 1 min. The filmthickness was measured before and after the immersion using aspectroscopic ellipsometer (UV 1280E, manufactured by KLA-TENCOR), and arate of change of the film thickness was calculated based on themeasured values. The solvent resistance was evaluated to be “A”(favorable) in a case where the rate of change of the film thickness wasless than 1%, to be “B” (somewhat favorable) in a case where the rate ofchange of the film thickness was no less than 1% and less than 5%, andto be “C” (unfavorable) in a case where the rate of change of the filmthickness was no less than 5%.

Flatness

Each of the compositions for forming a resist underlayer film ofExamples and Comparative Examples described above was applied on a SiO₂stepped substrate on which trenches having a width of 42 nm, a pitch of84 nm and a depth of 180 nm (aspect ratio: 4.3), trenches having a widthof 100 nm, a pitch of 150 nm and a depth of 180 nm (aspect ratio: 1.8),and trenches having a width of 5 m and a depth of 180 nm (open spaces;aspect ratio: 0.036) were provided in combination (the ratio of themaximum value to the minimum value of the aspect ratios in the pluralityof types of trenches: 119). Thereafter, baking was carried out at 250°C. for 60 sec under an ambient air atmosphere to form a resistunderlayer film having a film thickness of 200 nm. The shape of theresist underlayer film was observed using a scanning electron microscope(S-4800, manufactured by Hitachi High-Technologies Corporation), and thedifference of the maximum value and the minimum value of the filmthicknesses of the resist underlayer film on the Trench or spaces (ΔFT)was determined. The flatness was evaluated to be “S” (superior) in acase where the ΔFT was less than 10 nm, to be “A” (favorable) in a casewhere was no less than 10 nm and less than 20 nm, to be “B” (somewhatfavorable) in a case where the ΔFT was no less than 20 nm and less than35 nm; and to be “C” (unfavorable) in a case where the ΔFT was no lessthan 35 nm.

Outgas Inhibitory Ability

Each of the resist underlayer film-carrying substrate obtained above wascut into a rectangle of 1 cm×5 cm to prepare a sample for measurement.The amount of sublimates in heating of the sample for measurement at250° C. for 7 min using an automated P & T apparatus (JTD-505,manufactured by Japan Analytical Industry Co., Ltd.) was determinedusing a gas chromatography mass spectrometry apparatus (GC-MS) (6890N,manufactured by Agilent Technologies). It is to be noted that a resistunderlayer film formed from a composition for forming a resistunderlayer film (trade name “NFC CTL53”, manufactured by JSRCorporation) was used as a reference resist underlayer film. The outgasinhibitory ability was evaluated to be “A” (favorable) in a case wherethe amount of the sublimates of the sample for measurement was smalleras compared with the amount of the sublimates of the reference resistunderlayer film, to be “B” (somewhat favorable) in a case where nosignificant difference was not found between the amount of thesublimates of the sample for measurement and the amount of thesublimates of the reference resist underlayer film, and to be “C”(unfavorable) in a case where the amount of the sublimates of the samplefor measurement was greater as compared with the amount of thesublimates of the reference resist underlayer film.

Storage Stability

Each of the compositions for forming a resist underlayer film obtainedabove was stored at a temperature of 23° C., and after three months hadpassed, the molecular weight of the compound (A) contained wasdetermined, and the storage stability was evaluated. The storagestability was evaluated to be “A” (favorable) in a case where a changeof the molecular weight was not found, and to be “B” (unfavorable) in acase where the change of the molecular weight was found.

TABLE 3-1 Composition for Outgas forming resist Solubility EtchingSolvent inhibitory Storage underlayer film in PGMEA resistanceresistance Flatness ability stability Example 1 U-1  A S A S A A Example2 U-2  A A A A A A Example 3 U-3  A A A A A A Example 4 U-4  A B A A A AExample 5 U-5  A B A A A A Example 6 U-6  A A A S A A Example 7 U-7  A AA A A A Example 8 U-8  A S A A A A Example 9 U-9  A B A A A A Example 10U-10 A S A A A A Example 11 U-11 A S A S A A Example 12 U-12 A S A A A AExample 13 U-13 A A A S A A Example 14 U-14 A B A A A A Example 15 U-15A A A A A A Example 16 U-16 A B A A A A Example 17 U-17 A A A A A AExample 18 U-18 A A A A A A Example 19 U-19 A A A A A A Example 20 U-20A A A A A A

TABLE 3-2 Composition for Outgas forming resist Solubility EtchingSolvent inhibitory Storage underlayer film in PGMEA resistanceresistance Flatness ability stability Example 21 U-21 A S A S A AExample 22 U-22 A S A S A A Example 23 U-23 A S A S A A Example 24 U-24A A A S A A Example 25 U-25 A A A S A A Example 26 U-26 A B A B B AExample 27 U-27 A A B A A A Example 28 U-28 A A B A A A Comparative CU-1B A C C C A Example 1

As is seen from the results shown in Tables 3-1 and 3-2, the compositionfor forming a resist underlayer film according to the embodiment of thepresent invention enables a resist underlayer film superior in flatness,solvent resistance and outgas-inhibitory ability to be formed even on astepped substrate.

The composition for forming a resist underlayer film according to theembodiments of the present invention enables a resist underlayer filmsuperior in flatness, solvent resistance and outgas-inhibitory abilityto be formed. The pattern-forming method according to the embodiments ofthe present invention enables a resist underlayer film superior inflatness, solvent resistance and outgas-inhibitory ability to be formed,and in turn, a favorable pattern to be formed. Therefore, thecomposition for forming a resist underlayer film and the pattern-formingmethod can be suitably used for producing semiconductor devices in whichfurther progress of miniaturization is expected in the future.

The following Appendices are embodiments of the present invention.

Appendix 1

A composition for forming a resist underlayer film comprising:

a calixarene-based compound obtained from a calixarene by substitutingat least a part of hydrogen atoms each on phenolic hydroxyl groupscomprised in the calixarene, with a monovalent organic group having 1 to30 carbon atoms; and

an organic solvent.

Appendix 2

The composition for forming a resist underlayer film according toappendix 1, wherein the monovalent organic group comprises acrosslinkable group.

Appendix 3

The composition for forming a resist underlayer film according toappendix 1, wherein a part of hydrogen atoms each on phenolic hydroxylgroups of the calixarene-based compound is substituted.

Appendix 4

The composition for forming a resist underlayer film according toappendix 3, wherein a ratio of number of substituted phenolic hydroxylgroups to number of unsubstituted phenolic hydroxyl groups in thecalixarene-based compound is no less than 30/70 and no greater than99/1.

Appendix 5

The composition for forming a resist underlayer film according toappendix 1, wherein a viscosity of the composition for forming a resistunderlayer film at a solid content concentration of 20% by mass is noless than 1 cps and no greater than 5 cps.

Appendix 6

The composition for forming a resist underlayer film according toappendix 1, wherein the calixarene-based compound is derived from acompound obtained by subjecting a compound represented by a formula (1)and a compound represented by a formula (2) to a condensation reaction,

wherein in the formula (1), Y represents a hydrocarbon group having 1 to10 carbon atoms; q is an integer of 0 to 7; p is an integer of 1 to 3,wherein a sum of p and a is no less than 1 and no greater than 8; and kis 0 or 1, wherein in a case where q is no less than 2, a plurality ofYs are identical or different,

and wherein in the formula (2), X represents a substituted orunsubstituted hydrocarbon group having 1 to 30 carbon atoms and having avalency of j, or hydrogen atom; and j is 1 or 2.

Appendix 7

The composition for forming a resist underlayer film according toappendix 6, wherein the calixarene-based compound is represented by aformula (3),

wherein in the formula (3), R represents a hydrogen atom or a monovalentorganic group having 1 to 30 carbon atoms; m is an integer of 4 to 12;Y, k, p and q are as defined in the formula (1); and X is as defined inthe case where j in the formula (2) is 1, wherein a plurality of Rs areidentical or different, a plurality of Xs are identical or different, aplurality of “k”s are identical or different, a plurality of “p”s areidentical or different, and a plurality of “q”s are identical ordifferent, and wherein in a case where Y is present in a plurality ofnumber, a plurality of Ys are identical or different.

Appendix 8

The composition for forming a resist underlayer film according toappendix 6, wherein the calixarene-based compound is represented by aformula (4),

wherein in the formula (4), R represents a hydrogen atom or a monovalentorganic group having 1 to 30 carbon atoms; n is 2 or 3; Y, k, p and qare as defined in the formula (1); and X is as defined in the case wherej in the formula (2) is 2, wherein a plurality of Rs are identical ordifferent, a plurality of Xs are identical or different, a plurality of“k”s are identical or different, a plurality of “p”s are identical ordifferent, and a plurality of “q”s are identical or different, andwherein in a case where Y is present in a plurality of number, aplurality of Ys are identical or different.

Appendix 9

The composition for forming a resist underlayer film according toappendix 6, wherein the calixarene-based compound is represented by aformula (5),

wherein in the formula (5), R represents a hydrogen atom or a monovalentorganic group having 1 to 30 carbon atoms; Y, k, p and q are as definedin the formula (1); and X is as defined in the case where j in theformula (2) is 2, wherein a plurality of Rs are identical or different,a plurality of Xs are identical or different, a plurality of “k”s areidentical or different, a plurality of “p”s are identical or different,and a plurality of “q”s are identical or different, and wherein in acase where Y is present in a plurality of number, a plurality of Ys areidentical or different.

Appendix 10

The composition for forming a resist underlayer film according toappendix 1, wherein a molecular weight of the calixarene-based compoundis no less than 500 and no greater than 3,000.

Appendix 11

The composition for forming a resist underlayer film according toappendix 1, wherein the organic solvent comprises a polyhydric alcoholpartial ether acetate solvent, a ketone solvent, a carboxylic acid estersolvent, or a mixed solvent thereof.

Appendix 12

The composition for forming a resist underlayer film according toappendix 1, further comprising a resin other than resins correspondingto the calixarene-based compound.

Appendix 13

The composition for forming a resist underlayer film according toappendix 12, wherein the resin comprises a crosslinkable group.

Appendix 14

The composition for forming a resist underlayer film according toappendix 12, wherein the resin comprises a novolak resin, a resol resin,a styrene resin, an acenaphthylene resin, a polyarylene resin or amixture thereof.

Appendix 15

The composition for forming a resist underlayer film according toappendix 12, wherein a weight average molecular weight of the resin isno less than 2,000 and no greater than 8,000.

Appendix 16

The composition for forming a resist underlayer film according toappendix 12, wherein a content of the resin with respect to 100 parts bymass of the calixarene-based compound is no less than 5 parts by massand no greater than 1,000 parts by mass.

Appendix 17

The composition for forming a resist underlayer film according toappendix 1, wherein the composition is for use on a substrate having aplurality of types of trenches.

Appendix 18

The composition for forming a resist underlayer film according toappendix 17, wherein the plurality of types of trenches differ from oneanother in terms of an aspect ratio.

Appendix 19

The composition for forming a resist underlayer film according toappendix 18, wherein a ratio of a maximum value to a minimum value ofthe aspect ratios of the plurality of types of trenches is no less than10.

Appendix 20

A pattern-forming method comprising in a following order of:

providing a resist underlayer film directly or indirectly on asubstrate;

forming a resist pattern directly or indirectly on the resist underlayerfilm;

forming a pattern on the substrate through dry etching of the resistunderlayer film, the substrate, or both the resist underlayer film andthe substrate using the resist pattern as a mask; and

removing the resist underlayer film remaining on the substrate using abasic solution,

wherein the method further comprises subjecting the resist underlayerfilm to heating or an acid treatment before removing the resistunderlayer film, and

wherein the resist underlayer film is provided using the composition forforming a resist underlayer film according to appendix 1.

Appendix 21

The pattern-forming method according to appendix 20, wherein thesubstrate is stepped.

Appendix 22

The pattern-forming method according to appendix 20, wherein thesubstrate comprises a plurality of types of trenches.

Appendix 23

The pattern-forming method according to appendix 22, wherein theplurality of types of trenches differ from one another in terms of anaspect ratio.

Appendix 24

The pattern-forming method according to appendix 23, wherein a ratio ofa maximum value to a minimum value of the aspect ratios of the pluralityof types of trenches is no less than 10.

Appendix 25

The pattern-forming method according to appendix 20, comprising afterproviding the resist underlayer film and before forming the resistpattern:

providing an intermediate layer directly or indirectly on the resistunderlayer film,

wherein the intermediate layer is further dry etched in forming thesubstrate pattern.

Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically describedherein.

1: A composition comprising: a calixarene-based compound represented byformula (3); and an organic solvent,

wherein in the formula (3), R represents a hydrogen atom or a monovalentorganic group having 1 to 30 carbon atoms, and at least part of a partof R is the monovalent organic group; m is an integer of 4 to 12; Yrepresents a hydrocarbon group having 1 to 10 carbon atoms; q is aninteger of 0 to 7; p is an integer of 1 to 3, wherein a sum of p and gis no less than 1 and no greater than 8; and k is 0 or 1; X represents asubstituted or unsubstituted hydrocarbon group having 1 to 30 carbonatoms or a hydrogen atom, wherein a plurality of Rs are identical ordifferent, a plurality of Xs are identical or different, a plurality of“k”s are identical or different, a plurality of “p”s are identical ordifferent, and a plurality of “q”s are identical or different, andwherein in a case where Y is present in a plurality of number, aplurality of Ys are identical or different, wherein, in a case where pis 2, X is a phenyl group substituted with —OR; or the monovalentorganic group represented by R is at least one group selected from thegroup consisting of a benzyl group, a cyclopentyl group, a groupcomprising a polymerizable carbon-carbon triple bond, a group comprisingan epoxy group, a group comprising an alkoxymethyl group, a groupcomprising a formyl group, a group comprising an acetyl group, a groupcomprising a dialkylaminomethyl group, a group comprising adimethylolaminomethyl group, a group represented by formula (a), a grouprepresented by formula (b), and group represented by formula (c):

wherein R^(a) and R^(a′) each independently represent a single bond oran alkanediyl group having 1 to 10 carbon atoms: R^(a″) represents asingle bond, an alkanediyl group, a hydroxyalkanediyloxy group or(R″O)_(i); R″ represents an alkanediyl group: “i” is an integer of 1 to10; R^(b″) represents a hydrogen atom; and R^(b), R^(b′), R^(c), R^(c′),R^(c″), R^(d), R^(d′) and R^(d″) each independently represent a hydrogenatom or a monovalent hydrocarbon group. 2: The composition according toclaim 1, wherein the monovalent organic group represented by R comprisesa crosslinkable group. 3: The composition according to claim 1, whereina part of hydrogen atoms on phenolic hydroxyl groups of thecalixarene-based compound is substituted. 4: The composition accordingto claim 3, wherein a ratio of the number of substituted phenolichydroxyl groups to the number of unsubstituted phenolic hydroxyl groupsin the calixarene-based compound is no less than 30/70 and no greaterthan 99/1.
 5. (canceled) 6: The composition according to claim 1,wherein the calixarene-based compound is derived from a compoundobtained by subjecting a compound represented by formula (1) and acompound represented by formula (2) to a condensation reaction,

wherein in the formula (1), Y, k, p and q are as defined in the formula(3), and wherein in the formula (2), X is as defined in the formula (3);and j is 1 or
 2. 7-9. (canceled) 10: The composition according to claim1, wherein a molecular weight of the calixarene-based compound is noless than 500 and no greater than 3,000. 11: The composition accordingto claim 1, wherein the organic solvent comprises a polyhydric alcoholpartial ether acetate solvent, a ketone solvent, a carboxylic acid estersolvent, or a mixed solvent thereof. 12: The composition according toclaim 1, further comprising a resin other than a resin corresponding tothe calixarene-based compound. 13: The composition according to claim12, wherein the resin other than the resin corresponding to thecalixarene-based compound comprises a crosslinkable group. 14: Thecomposition according to claim 12, wherein the resin other than theresin corresponding to the calixarene-based compound comprises a novolakresin, a resol resin, a styrene resin, an acenaphthylene resin, apolyarylene resin or a mixture thereof. 15: The composition according toclaim 12, wherein a weight average molecular weight of the resin otherthan the resin corresponding to the calixarene-based compound is no lessthan 2,000 and no greater than 8,000. 16: The composition according toclaim 12, wherein a content of the resin other than the resincorresponding to the calixarene-based compound with respect to 100 partsby mass of the calixarene-based compound is no less than 5 parts by massand no greater than 1,000 parts by mass. 17-19. (canceled) 20: Apattern-forming method comprising: applying the composition according toclaim 1 directly or indirectly on a substrate to provide a resistunderlayer film; forming a resist pattern directly or indirectly on theresist underlayer film; forming a pattern on the substrate through dryetching of the resist underlayer film, the substrate, or both the resistunderlayer film and the substrate using the resist pattern as a mask;and removing the resist underlayer film remaining on the substrate usinga basic solution, wherein the method further comprises subjecting theresist underlayer film to heating or an acid treatment before removingthe resist underlayer film. 21: The pattern-forming method according toclaim 20, further comprising after providing the resist underlayer filmand before forming the resist pattern: providing an intermediate layerdirectly or indirectly on the resist underlayer film, wherein theintermediate layer is further dry etched in forming the pattern. 22: Thecomposition according to claim 1, wherein the monovalent organic grouprepresented by R is the group represented by the formula (b).